The endocannabinoid system is modulated in response to spinal cord injury in rats.
Endocannabinoids are lipid mediators with protective effects in many diseases of the nervous system. We have studied the modulation of the endocannabinoid system after a spinal cord contusion in rats. In early stages, lesion induced increases of anandamide and palmitoylethanolamide (PEA) levels, an upregulation of the synthesizing enzyme NAPE-phospholipase D and a downregulation of the degradative enzyme FAAH. In delayed stages, lesion induced increases in 2-arachidonoylglycerol and a strong upregulation of the synthesizing enzyme DAGL-alpha, that is expressed by neurons, astrocytes and immune infiltrates. The degradative enzyme MAGL was also moderately increased but only 7 days after the lesion. We have studied the cellular targets for the newly formed endocannabinoids using RT-PCR and immunohistochemistry against CB(1) and CB(2) receptors. We observed that CB(1) was constitutively expressed by neurons and oligodendrocytes and induced in reactive astrocytes. CB(2) receptor was strongly upregulated after lesion, and mostly expressed by immune infiltrates and astrocytes. The endocannabinoid system may represent an interesting target for new therapeutical approaches to spinal cord injury.
Garcia-Ovejero
Daniel
D
Laboratorio de Neuroinflamacion, Unidad de Neurología Experimental (Research Unit associated to the Instituto Cajal, CSIC, Madrid), Hospital Nacional de Paraplejicos, Toledo, Spain.
Arevalo-Martin
Angel
A
Petrosino
Stefania
S
Docagne
Fabian
F
Hagen
Carlos
C
Bisogno
Tiziana
T
Watanabe
Masahiko
M
Guaza
Carmen
C
Di Marzo
Vincenzo
V
Molina-Holgado
Eduardo
E
D000577:Amides; D000581:Amidohydrolases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism; D001253:Astrocytes / Q000378:metabolism; D063385:Cannabinoid Receptor Modulators / Q000378:metabolism*; D063388:Endocannabinoids; D004983:Ethanolamines; D005989:Glycerides / Q000378:metabolism; D007150:Immunohistochemistry; D008071:Lipoprotein Lipase / Q000235:genetics / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D008297:Male; D009474:Neurons / Q000378:metabolism; D010169:Palmitic Acids / Q000378:metabolism; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism; D053284:Polyunsaturated Alkamides / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism; D043885:Receptor, Cannabinoid, CB2 / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000378:metabolism*; D013119:Spinal Cord Injuries / Q000201:enzymology / Q000378:metabolism*; D000099252:Fatty Acid Amide Hydrolases
D000577:Amides; D000581:Amidohydrolases; D001095:Arachidonic Acids; D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D004983:Ethanolamines; D005989:Glycerides; D008071:Lipoprotein Lipase; D010169:Palmitic Acids; D010739:Phospholipase D; D053284:Polyunsaturated Alkamides; D012333:RNA, Messenger; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D000099252:Fatty Acid Amide Hydrolases; C469526:Cnr2 protein, rat; C005958:palmidrol; C094503:glyceryl 2-arachidonate; C527163:Napepld protein, rat; C078814:anandamide